1. FIELD OF THE INVENTION
This invention relates to a tubular fuel rail for supplying fuel to a plurality of electromagnetic fuel injectors for a multicylinder internal combustion engine. More specifically it relates to a fuel rail having a plurality of spaced apart bulbous or nodular sections defining fuel sumps which contain recessed sockets. Fuel is supplied to the fuel injectors through apertures in the sockets. The fuel sumps are connected together in series by tubular arteries or ducts having cross sectional openings of reduced size.
2. DESCRIPTION OF THE PRIOR ART
Prior art fuel rails may have functioned acceptably but many were made up of a large number of separate parts. The large number of parts resulted in unnecessary manufacturing costs and difficulties, particularly in placing the parts in their relative positions and integrally connecting and sealing the parts together. Some of the early fuel rails were bulky and interferred with access to the injectors or to adjacent parts. Occasionally audible noise would develop as a result of a resonant interaction caused by the timed movement of fuel into the injectors. Another problem which may be related to resonance was that injector outputs varied depending upon the location of the injector. Apparently turbulence or some other unexplained internal factor affected the distribution of fuel to the separate injector sites and caused this lack of uniformity. In some prior art fuel rails the injector sockets were located below the fuel in the body of the fuel rail and thus water and dirt could easily gravitate directly into the top of the injector sockets and be inducted into the injectors.
The invention disclosed herein solves a number of these problems by forming the injector sockets directly in the bottom half of the fuel rail. The sockets are recessed into the rail rather than projecting below it. This allows for a reduction in the height of the rail. The bulbous sump chamber sections appear to dampen or attenuate noise impulses produced by the pulsed flow of fuel into the injectors. The combination of bulbous sump sections connected by narrow tubular arteries appears to prevent resonant noise buildup from one sump to another. This combination also provides a marked improvement in injector output uniformity. An annular portion of the sump chamber surrounding the bottom of each injector socket provides a depression for collecting any water or dirt particles that accidently enters the fuel rail.